precision lowp float;
varying vec2 vUv;
varying float vElevation;

// uniform sampler2D uTexture;

void main(){
  float height =  (vElevation + 1.3) * 2.0;
    gl_FragColor = vec4(1.0 * height, 0.0 ,0.0, 1.0);
  // 根据uv进行采样,取出对应的颜色


  // vec4 textureColor = texture2D(uTexture,vUv);
  // textureColor.rbg *= height;
  // gl_FragColor = textureColor;
}